Biochar-synergy in anaerobic digestion of animal wastes for total pollution control and bioenergy production: A sustainable integrated perspective

Organic waste disposal and treatment are key public and environmental health issues contributing to pollution reduction and minimizing the spread of diseases from agricultural setups. Current treatment methods of animal waste often generate odors and greenhouse gases, which become catastrophic downstream, including algae blooms and groundwater contamination. Anaerobic digestion (AD) using bioreactors has been an economic resource utilization strategy for organic waste treatment with ecological integrity for environmental justice. To enhance the effectiveness of AD, the addition of biochar has been shown to improve treatment efficiency by amplifying bacterial activity and aiding in the breakdown of complex organic materials for biofuel production. We reviewed the integration of biochar in the AD of animal waste material as a cost-effective bio-carrier to enhance treatment for environmental protection and bioenergy production. We discussed the current relationship between pyrolysis conditions and feedstock types used in the AD process and evaluated the ecological functions of microbial activities and their interaction with biochar-based biomass in AD engineering designs. A comprehension of the technological advances to improve the AD performances associated with microbial biomass and biochar addition and potential areas for future research and their limitations toward a zero-waste paradigm for sustainable development in farm management systems was reviewed.